A REVISED GENUS-LEVEL CLASSIFICATION OF THE GLASSPERCH FAMILY AMBASSIDAE (TELEOSTEI) USING GENETIC MARKERS

Siti Zafirah Ghazali ^1*, Sébastien Lavoué², Tan Min Pau¹, Siti Azizah Mohd Nor¹

¹ Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu,Terengganu, Malaysia.

² School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia

^*Corresponding author: sitizafirahghazali@gmail.com

The generic classification of the glassperch family Ambassidae (Teleostei) was last revised in 1955 by Alvin Fraser-Brunner, mostly based on head serration characteristics. However, significant confusion on how to identify ambassid genera still prevails due to several factors, suggesting that the taxonomy of this family needs further investigations. Such investigations include (1) the discovery and description of new species and new genera, (2) the detection of cryptic diversity within widely distributed species and (3) the definition of supra-specific taxa (such as genera) using morphological and/or molecular synapomorphies. The latter point should be based on a good understanding of the phylogenetic relationships among ambassid species but a phylogenetic hypothesis for the whole family is currently lacking. In this study, we address this issue in building a comprehensive molecular phylogenetic tree for the purpose of revising the genus-level classification of Ambassidae. Our dataset comprises of 49 individuals representing 33 species (out of 54 species) and six genera (out of 7 genera) using five DNA markers (COI, cytochrome b, 16S, RAG1 and rhodopsin). Our results indicate that the two largest genera of Ambassidae, Ambassis and Parambassis, are each not monophyletic and the taxonomy and classification of these two genera must therefore be revised. We propose a modified classification of Ambassidae comprising ten genera (including Tetracentrum which was not available for our study). Published names are available for eight of these genera whereas two genera are undescribed and unnamed. The molecular results presented in this study can serve as a support of further morphological examination.

Keywords: Ambassidae, glassperch, RAxML, phylogeny, taxonomy

DISTINCT COI SEQUENCES BETWEEN FRESHWATER AND BRACKISH POPULATIONS REVEALED TWO POSSIBLE CRYPTIC SPECIES OF Plotosus canius (HAMILTON, 1822)

Nhu-Y Thi Nguyen^1,*, Thuy-Yen Duong²

¹Advanced Program in Aquaculture Course 44, College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Viet Nam

²College of Aquaculture and Fisheries, Can Tho University, Can Tho City, Viet Nam

^*Corresponding author: yb1800980@student.ctu.edu.vn

Grey-eel catfish (Plotosus canius) is the only species of the Plotosidae family previously reported in the Mekong Delta. This catfish species distributes in a wide range of salinity levels, raising the question whether there are morphological and genetic differences between the freshwater and brackish water populations. To look for the answer, we analyzed morphological characteristics and the cytochrome c oxidase 1 (COI) gene of the grey-eel catfish samples collected from 4 provinces, including An Giang (n=29), Soc Trang (n=47), Tra Vinh (n=40) and Bac Lieu (n=26). Meristic traits, including the number of fin rays, the number of gill rackers on the first arch and the number of vertebrate posterior to the Weberian complex, had similar ranges among four fish populations (P>0.05). Morphometric indices, the ratios of measurements to standard length and head length, were significantly different among populations (P<0.05). The adjusted morphometric indices, after eliminating the effect of body length, were employed for Principal component analysis (PCA) and Discriminant analysis (DA). DA could categorize individuals into their original populations with the correct assignments from 80% to 90%. However, meristic traits and morphometric indices overlapped among samples from the four populations, failing to distinguish P.canius between freshwater and brackish water environments. On the contrary, genetic identification based on 611 base- pair COI sequences from 33 samples revealed two distinct groups of freshwater and brackish water with 47.32±6.28 nucleotide differences and genetic distance (K2P) of 8.33%±1.2. This level of nucleotide difference can be interspecific distance, indicating two possible species of Plotosus. Therefore, two morphologically similar groups of grey-eel catfish distributed in freshwater and brackish water can be two cryptic species based on COI evidence.

Keywords: COI sequences, genetic difference, morphology, Plotosus canius, salinity

MOLECULAR IDENTIFICATION OF SILVER-BARB (Barbonymus sp.) BASED ON COI AND Cyt-b GENE REGION FROM EAST JAVA

Mutiara Rahmawati¹, Akhmad Taufiq Mukti², Sapto Andriyono^3,*

¹Graduated Program on Biotechnology of Fisheries and Marine, Faculty of Fisheries and Marine, Universitas Airlangga, Campus C Mulyorejo, Surabaya 60115, Indonesia

²Departement of Aquaculture, Faculty of Fisheries and Marine, Universitas Airlangga, Campus C Mulyorejo, Surabaya 60115, Indonesia

³Departement of Marine, Faculty of Fisheries and Marine, Universitas Airlangga, Campus C Mulyorejo, Surabaya 60115, Indonesia

^*Corresponding author: sapto.andriyono@fpk.unair.ac.id     

This study aims to determine the genetic character of cyprinid fish (Barbonymus sp.) using the mitochondrial DNA (mtDNA) gene in the Cytochrome C Oxidase subunit I (COI) and Cytochrome-b (Cyt-b) gene regions. Samples were collected from various areas in East Java Province, including Gresik, Mojokerto, Madiun, Malang, and Banyuwangi. The caudal peduncle of the cyprinid fish was used for molecular identification. Isolation and purification of its genomic DNA using the gSYNCTM DNA Extraction kit. We used a polymerase chain reaction machine for template DNA amplification with COI primers, including FishF1 and FishR1, while Cyt-b primers, including GluDG-L and CB2-H. The results showed that all cyprinid fish sequences were successfully amplified with the COI gene of 648 bp and the Cyt b gene of 408 bp. The results of the BLASTN analysis show that there are two species of cyprinid fish that have been found, namely Barbonymus gonionotus and Barbonymus schwanenfeldii, with percentage identities ranging from 99-100%. Barbonymus gonionotus was found in five regions (Gresik, Mojokerto, Madiun, Malang, and Banyuwangi), while Barbonymus schwanenfeldii was only found in Malang. The genetic distance value based on the COI gene ranged from 0.00000-0.10694, while the genetic distance value based on the Cyt-b gene ranged from 0.00000-1.15662. Conservation status based on IUCN Red List data, the species Barbonymus gonionotus and Barbonymus schwanenfeldii are included in the Least Concern (LC) category, and these species, according to CITES data, have not been evaluated or Not Evaluated.

Keywords: diversity, fish, gene, molecular identification

THE COMPLETE MITOCHONDRIAL GENOMES OF Pangasius nasutus AND P. conchophilus: INSIGHT INTO THEIR STRUCTURAL FEATURES AND PHYLOGENETIC IMPLICATIONS

Siti Amalia Aisyah Abdul Halim1, Yuzine Esa1* and Siti Azizah Mohd Nor2

1Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

2Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

*Corresponding author: ameliaaisya245@gmail.com

Pangasius nasutus and P. conchophilus are commercially important species of catfish in the genus Pangasius. These two species are often misidentified with each other because of their morphological and genetic similarities. Thus, the current study was conducted to differentiate them based on a molecular approach. The complete mitochondrial genomes of P. nasutus and P. conchophilus were sequenced, assembled, and annotated using Next-generation sequencing (NGS). A 16,465 bp and 16,470 bp length mitogenome sequences of P. nasutus and P. conchophilus, respectively were generated, each containing 13 protein genes, 22 tRNAs, and two rRNAs, typical of most vertebrates. The overall base compositions include; P. nasutus (A: 31.3%, T: 26.1%, G: 15.1%, C: 27.5%.) and P. conchophilus (A: 31.2%, T: 26.1%, G: 15.1%, C: 27.6%). The phylogenetic study revealed two main clusters (A and B) of available mitogenomes within the family Pangasiidae. The results of the phylogenetic tree supports P. nasutus has a closest relationship with P. conchophilus with high support (BP:100%). These findings provide a genetic basis for the evolutionary connection of the Pangasiidae family and shed light on the uniqueness of the mitochondrial genomes of P. nasutus and P. conchophilus. This data is also a valuable genetic resource for future studies of these two commercially important species. This is the first report of the complete mitochondrial genome sequences of P. nasutus and P. conchophilus.

Keywords: Pangasius nasutus, P. conchophilus, phylogenetic, mitochondrial genome, Next- generation sequencing (NGS)

MtDNA CYT B REVEALED NO GENETIC DIFFERENCE BETWEEN GEOGRAPHICALLY DISTANT POPULATIONS OF Pangasius conchophilus IN THE MEKONG RIVER

Ngoc-Tran Thi Nguyen^1,*, Thuy-Yen Duong¹

¹College of Aquaculture and Fisheries, Can Tho University, Viet Nam

^*Corresponding author: ntntran@ctu.edu.vn

Pangasius conchophilus Roberts & Vidthayanon, 1991, which belongs to the family Pangasiidae, is a common and high economic value species distributed in the Mekong River. The study aimed to investigate the level of genetic diversity of P. conchophilus in Laos and Viet Nam representing two locations upstream and downstream of the Mekong River using mtDNA cytochrome b (cyt b) gene. A total of 75 individuals were collected from two P. conchophilus populations in Viet Nam, including Can Tho (CT, n=22) and An Giang (AG, n=26), and two populations in Laos, including Pakse (PE, n=8) and Paksan (PA, n=19), were sequenced by cyt b gene. The sequencing results of 657 bp cyt b fragments revealed a moderate level of genetic diversity compared to other Pangasius species with the value of haplotype diversity (Hd) and nucleotide diversity (Pi) ranging from 0.844 to 0.964  and 0.005 to 0.007, respectively. Intra-specific K2p genetic distance of this species was also calculated showing that the Laos populations (K2p = 0.57 – 0.71%) had a slightly higher genetic distance than Viet Nam populations (K2p = 0.56 – 0.63%). Similar to the above levels, the K2p genetic distance between populations of P. conchophilus ranged from 0.54 to 0.70 %. The phylogenetic tree of haplotypes revealed two groups with a similar value of K2p genetic distance (0.89%) compared to those between four populations. Each haplotype group had representative samples from all populations. These results indicated no genetic differentiation between geographically distant populations, implying a long migration pattern of the species along the mainstream of the Mekong River.

Keywords: Genetic differentiation, Genetic variation, Migration, Pangasius conchophilus

CYTOGENETIC OF WHIPFIN MOJARRA (GERRES FILAMENTOSUS) FROM PATTANI, THAILAND

Napapun Sama-e¹, Sitthisak Jantarat^2*, Sukree Hajisamae¹, Alongkod Tanomtong³, Nattasuda Donbundit³

¹Department of Technology and Industry, Faculty of Science and Technology, Prince of Songkla University, Mueang, Pattani, 94000, Thailand

²Department of Science, Faculty of Science and Technology, Prince of Songkla University, Mueang, Pattani, 94000, Thailand

³Department of Biology, Faculty of Science, Khonkaen Uniiversity, Mueang, Khonkaen 44000, Thailand

^*Corresponding author: sitthisak.j@psu.ac.th

This study examines for the first time of karyotypic analysis of Gerres filamentosus (Perciformes: Gerridae). The fish samples were collected from Pattani bay, Pattani province, southern Thailand. The chromosomes were investigated using conventional Giemsa’s staining. The Metaphase chromosome preparations were conducted by squash technique from kidney cells of five male and five female fishes. The diploid chromosome number of this species composed by 50 telocentric chromosomes (2n=50, FN=50). No heteromorphic sex chromosomes were cytologically detected.

Keywords: Karyotype, Chromosome, Gerres filamentosus